Surfactant composition

ABSTRACT

To provide a surfactant composition with an excellent foamability and thickening performance and further an excellent storage stability, it comprises the following components (a) and (b):  
     (a) at least one anionic surfactant selected from (1) sulfonate-type anionic surfactants having amide group or ester group, (2) carboxylate-type anionic surfactants and (3) phosphate-type anionic surfactants and  
     (b) a compound expressed by the formula (I):  
                 
 
     where R 1 CO— is an acyl group having 6 to 24 carbon atoms, R 2  is an alkyl group having 1 to 3 carbon atoms and R 3  is an alkylene group having 1 to 6 carbon atoms or an alkenylene group having 2 to 6 carbon atoms.

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a surfactant composition havingan excellent foamability, thickening performance and water solubilityand further an excellent storage stability.

PRIOR ARTS

[0002] Not only a high detergency but also an abundant foaming arerequested to a detergent such as a shampoo, a rinse, a solid soap, abody shampoo, a detergent for kitchens, a detergent for clothing and adetergent for dwellings. One which has been widely used as the main basein many products is an anionic surfactant such as an alkylbenzenesulfonate (LAS) , an alkyl sulfate salt (AS) and apolyoxyethylene alkyl sulfate salt (AES) However, although any thereofusually shows its excellent detergency and foaming, there is a problemtherein that, when solids, a stain derived from silicone or the like ispresent, the detergency and foamability significantly lower.

[0003] Further, in the recent trend of seeking detergents small in loadto the human body and the environment, anionic surfactants of the baseare not limited to LAS, AS, or AES, but various surfactants have come tobe used widely. Examples are diversified, including carbonates usingalkyl phosphate or amino acid as the raw material, and sulfonates andcarbonates using amide group, ester group, or other functional group toseek safety and biodegradable property. These surfactants used as thebase generally tend to lower in detergency and formability as thediversity is emphasized.

[0004] In order to improve such a lowering in detergency and/orfoamability, various co-surfactants besides the main base have beeninvestigated. There have been first proposed a fatty acid diethanolamidewhich has been actually and widely used in the products and thenproposed in recent years a fatty acid monoethanolamide (WO 98/0507, WO97/44434, JP-A11-80785, etc.), a sugar amide-type nonionic surfactant(WO94/12610), an acylsarcosinate (WO 96/06596), etc. However, althoughthese detergent compositions are improved in detergency and foamability,they are not well satisfactory yet.

[0005] JP-A 2001-34310, being equivalent to WO 01/40421 published onJun. 7, 2001 corresponding to EP-A 1149892, discloses an ethanol amidecompound.

[0006] It is also important to suppress separation of a blend caused instorage or adjust the viscosity of the blend so adequately as to producea proper comfort in use. Those above shown auxiliary surfactantsfunction as a thickening agent for the principal base. Since most ofthem are solid at a room temperature, however, separation easily occursin storage. No storage stability is satisfactory.

SUMMARY OF THE INVENTION

[0007] A purpose of the invention is to provide a surfactant compositionhaving an excellent foamability and thickening performance and then anexcellent storage stability.

[0008] The invention provide a surfactant composition comprising thefollowing components (a) and (b):

[0009] (a) at least one anionic surfactant selected from the groupconsisting of (1) to (3) defined below:

[0010] (1) a sulfonate-type anionic surfactant having an amide group oran ester group,

[0011] (2) a carboxylate-type anionic surfactant,

[0012] (3) a phosphate-type anionic surfactant,

[0013] (b) a compound prepresented by the formula (I):

[0014] where R¹CO— is a saturated or unsaturated acyl group having 6 to24 carbon atoms which may have a hydroxy group, R²is an alkyl grouphaving 1 to 3 carbon atoms and R³ is a linear or branched chain alkylenegroup having 1 to 6 carbon atoms or a linear or branched chainalkenylene group having 2 to 6 carbon atoms.

[0015] The composition of the invention comprises (a) the anionicsurfactant and (b) the N-alkanol-N-alkyl fatty acid amide incombination. (a) is limited to the specified species and (b) is providedwith an excellent thicking property and an excellent foamability.

DETAILED DESCRIPTION OF THE INVENTION

[0016] The component (a) of the invention is an anionic surfactantselected from (1) to (3) shown above. One or a plurality of them maybeused. Among these anionic surfactants, (2) or (3) is preferred.

[0017] Examples of the sulfonate-type anionic surfactant (1) include anacylated amino sulfonic acid and a salt thereof, represented in theformula (II):

[0018] where R⁴CO— is a saturated or unsaturated acyl group having 6 to24 carbon atoms, R⁵ is a hydrogen atom or a linear or branched chainalkyl group having 1 to 3 carbon atoms which may possess —OH, —CN or—COOH as a substituent, preferably being a hydrogen atom or methylgroup, R⁶ is a linear or branched chain alkylene group having 1 to 4carbon atoms or a linear or branched chain alkenylene group having 2 to4 carbon atoms and M is a hydrogen atom, an alkali metal, an alkalineearth metal, ammonium or an alkanol amine;

[0019] an acylated hydroxyl sulfonic acid and a salt thereof,represented by the formula (III):

[0020] where R⁴CO— and M are the same as defined above and R⁷is a linearor branched chain alkylene group having 1 to 4 carbon atoms or a linearor branched chain alkenylene group of 2 to 4 carbon atoms;

[0021] a sulfonated compound of a lower alkyl ester of a fatty acidhaving 6 to 24 carbon atoms and a salt thereof, the alkyl preferablyhaving 1 to 3 carbon atoms; and

[0022] a sulfonated compound of a mono- or di-alkyl ester of adicarboxylic acid of 3 to 9 carbon atoms and a salt thereof, the alkylgroup preferably having 1 to 24 carbon atoms, more preferably 1 to 12.

[0023] More specifically is used at lease one of an acylatedisethionate, an N-acyltaurate, an N-acyl-N-methyltaurate, a mono- ordi-ester of sulfosuccinic salt and an α-sulfonated fatty acid estersalt.

[0024] All these sulfonate-type anionic surfactants have an acyl grouphaving an amide group or an ester group. The acyl group is preferably asaturated or unsaturated group having 6 to 24 carbon atoms, morepreferably 8 to 18 carbon atoms. Specific examples are acyl groupsderived from octanoic acid, decanoic acid, dodecanoic acid,tetradecanoic acid, hexadecanoicacid, octadecanoic acid, docosanoicacid, linolic acid, 2-ethyl hexanoic acid, 2-octyl undecanoic acid,isostearic acid, oleic acid, coconut oil fatty acid, palm oil fattyacid, palm kernel oil fatty acid, tallow fatty acid, etc. Among theseacyl groups, those containing 50 wt. % or more of an acyl group derivedfrom a fatty acid having 12 to 14 carbon atoms are further preferable.

[0025] Examples of the carboxylate-type surfactant (2) include soap, analkylethoxycarboxylate, an acylated amino acid salt, etc. As the soap, afatty acid salt having 6 to 24 carbon atoms is preferred. Specificexamples are octanoate, decanoate, dodecanoate, tetradecanoate,hexadecanoate, octadecanoate, docosanoate, linoleate, 2-ethylhexanoate,2-octylundecanoate, isostearate, oleate, coconut oil fatty acid salt,palm oil fatty acid salt, palm kernel oil fatty acid salt, tallow fattyacid salt and a mixture thereof.

[0026] A preferred alkylethoxycarboxylate is expressed by the formula(IV):

R⁸O(CH₂CH₂O)_(n)CH₂COOM   (IV)

[0027] where R⁸ is a linear or branched chain alkyl or alkenyl grouphaving 6 to 24 carbon atoms, n is a number of from 0 to 20 and M is thesame as defined above.

[0028] A preferred acylated amino acid salt includes an acylsarcosinate, an acyl glutamate, an acyl alanate and an acyl glycinate,having 6 to 24 carbon atoms in the acyl group, preferably 8 to 18.

[0029] Examples of the phosphate-type anionic surfactant (3) arephosphates expressed by the formulae (V) and (VI):

[0030] where R⁹, R¹⁰, and R¹¹ are a linear or branched chain alkyl oralkenyl group of 8 to 18 carbon atoms, M is the same as defined aboveand plural M's may be either the same as or different from one anotherand x, y, and z are a number of from 0 to 10.

[0031] One or more of them may be used. A preferred phosphate has alinear or branched chain alkyl of 8 to 14 carbon atoms and the averageaddition mole number of ethylene oxide, expressed by x, y, z, of 0 to 6.The compound expressed by the formula (V) is particularly preferred.

[0032] A counter ion, expressed by M in formulas (II) to (VI) to formthe anionic surfactants of (1) to (3) is selected from a hydrogen atom,an alkali metal, an alkaline earth metal, ammonium and an alkanol aminehaving a hydroxyl alkyl group of 2 to 3 carbon atoms. A preferredexample thereof is hydrogen atom, sodium, potassium, magnesium, calcium,ammonium or mono-, di- or tri-ethanol amine, more preferably beinghydrogen atom, sodium, potassium or ammonium.

[0033] In the component (b) of the present invention, R¹CO— is an acylgroup as mentioned above. It is preferably a saturated or unsaturatedacyl group having 8 to 18 carbon atoms. It includes for example an acylgroup derived from octanoic acid, decanoic acid, dodecanoic acid,tetradecanoic acid, hexadecanoic acid, octadecanoic acid, docosanoicacid, linoleic acid, 2-ethylhexanoic acid, 2-octylundecanoic acid,isostearic acid, oleic acid, coco-fatty acid, a palm oil-fatty acid, apalm kernel oil-fatty acid or a tallow-fatty acid.

[0034] It is preferable among the acyl groups to include 50 wt. % ormore of an acyl group derived from a fatty acid having 12 to 14 carbonatoms. It is more preferable to include 40 to less than 100 wt. % of anacyl group derived from a fatty acid having 12 carbon atoms.

[0035] In order not to lower foamability, R² is a linear or branchedalkyl group having 1 to 3 carbon atoms, preferably methyl group or ethylgroup. Methyl group is in particular preferable. In order not to lowerthe surface-active performance, R³ is a linear or branched alkylenehaving 1 to 6 carbon atoms or an alkenylene group having 2 to 6 carbonatoms. It is preferably a linear or branched alkylene group having 2 or3 carbon atoms.

[0036] The component (b) includes, for instance,N-(2-hydroxyethyl)-N-methyl octanamide, N-(2-hydroxyethyl)-N-methyldecanamide, N- (2-hydroxyethyl) -N-methyl dodecanamide,N-(2-hydroxyethyl)-N-methyl tertadecanamide, N-(2-hydroxyethyl)-N-methylhexadecanamide, N-(2-hydroxyethyl)-N-methyl octadecanamide,N-(2-hydroxyethyl)-N-methyl-coco-fatty carboxamide,N-(2-hydroxyethyl)-N-methyl-palm kernel oil-fatty carboxamide,N-(2-hydroxypropyl)-N-ethyl dodecanamide, N-ethyl-N-(2-hydroxypropyl)oleamide and N-ethyl-N-(2-hydroxypropyl) isostearamide.

[0037] A method for producing the component (b) is not particularlylimited. For example, it can be produced by a condensation reaction or ade-alcohol reaction of a fatty acid or a lower alcohol ester of a fattyacid with an alkanolamine, a reaction of a fatty acid halide with analkanolamine in the presence of an alkaline catalyst, an ester-amideexchanging reaction (an aminolysis) between fats and oils and analkanolamine or others. The product obtained by such a method may oftencontain small amounts of fatty acids, inorganic salts, glycerol and thelike.

[0038] The blending rate of the component (a) to the component (b) inthe composition of the invention is preferred to be a ratio by weight of(a)/(b)=99/1 to 50/50 from the viewpoint of foamability and thickening,more preferably 98/2 to 90/10.

[0039] The sum total of the components (a) and (b) in the composition ofthe invention is preferred to be 5 to 100 wt. % from the viewpoint of anexcellent surface activity, more preferably 10 to 100 wt. %.

[0040] In addition to the essential components (a) and (b), in theinvention, at least one selected from group consisting of a compoundexpressed by the formula (VII) (hereinafter called compound VII) and acompound expressed by the formula (VIII) (hereinafter called compoundVIII) may be blended:

[0041] in the formula, R¹CO—, R² and R³ of the formulae have the samemeanings as above shown and, in each compound, R¹, R² and R³ may be thesame as or different from one another.

[0042] The compound represented by the formula (VII) includes, forinstance, N-octanoyl-N-methylaminoethyl octanoate,N-octanoyl-N-methylaminoethyl decanoate, N-octanoyl-N-methylaminoethyldodecanoate, N-octanoyl -N-methylaminoethyl tetraecanoate,N-octanoyl-N-methylaminoethyl hexadecanoate,N-octanoyl-N-methyaminoethyl octadecanoate,N-dodecanoyl-N-methylaminoethyl octanoate,N-dodecanoyl-N-methylaminoethyl decanoate, N-dodecanoyl-N-methylaminoethyl dodecanoate, N-dodecanoyl-N-methylaminoethyltetradecanoate, N-dodecanoyl-N-methylaminoethyl hexadecanoate,N-dodecanoyl-N-methylaminoethyl octadecanoate,N-dodecanoyl-N-ethylaminohexyl octanoate, N-dodecanoyl-N-ethylaminohexyldecanoate, N-dodecanoyl-N-ethylaminohexyl dodecanoate,N-dodecanoyl-N-ethylaminohexyl tetradecanoate,N-dodecanoyl-N-ethylaminohexyl hexadecanoate,N-dodecanoyl-N-ethylaminohexyl octadecanoate, coco-fatty acid(N-cocoyl-N-methylaminoethyl)ester and palm kernel oil fatty acid(N-palm kerneloyl-N-methylaminoethyl ester.

[0043] Examples of the compound represented by the formula (VIII), forinstance, include 2- (methylamino)ethyl octanoate, 2-(methylamino)ethyldecanoate, 2-(methylamino)-ethyl dodecanoate, 2-(methylamino)ethyltetradecanoate, 2-(methylamino)ethyl hexadecanoate, 2-(methylamino)ethyloctadecanoate, 2-(methylamino)ethyl oleate, 2-(ethylamino)ethyloctanoate, 2- (ethylamino) ethyl dodecanoate, 2-(ethylamino)ethyltetradecanoate, 2-(ethylamino)ethyl hexadecanoate, 2-(ethylamino)ethyloctadecanoate, 2-(ethylamino)ethyl oleate, 2-(methylamino)propyloctanoate, 2-(methylamino)propyl decanoate, 2-(methylamino)propyldodecanoate, 2-(methylamino)propyl tetradecanoate, 2-(methylamino)propylhexadecanoate, 2-(methylamino)propyl octadecanoate,2-(methylamino)propyl oleate, a coco-fatty acid(2-ethylaminoethyl) esterand palm kernel fatty acid (2-ethylaminoethyl) ester.

[0044] The total blending amount of the compounds VII and VIII to thecomponent (b) is preferably a rate by weight of (b)/(VII and VIII) of99.99/0.01 to 80/20.

[0045] In addition to the above shown components, in the invention, ananionic surfactant other than the component (a) a cationic surfactant, anon-ionic surfactant, an amphoteric surfactant or a mixture thereof maybe added as another component.

[0046] The surfactant composition of the invention can exhibit thecharacteristics sufficiently, regardless of its pH value. In particular,a preferred foamability and thickening property can be obtained in thepH range of 3.0 to 11.0.

EXAMPLES Examples 1 to 7, Comparative Examples 1 to 7

[0047] Using the following components, various surfactant compositionsshown in Table 1 were prepared and then evaluatead in view offoamability and storage stability by the following methods. Results areshown in Table 1. The viscosity was also determined by the followingmethod. Results are shown in Table 2.

Components

[0048] Component (a)

[0049] a-1: sodium a sulfonated lauric acid methylester

[0050] a-2: Sodium lauryl ethoxy (3) acetate

[0051] a-3: Sodium laurate

[0052] a-4: potassium monolauryl phosphate

[0053] a-5: potassium monolauryl ethoxy (3) phosphate

[0054] Component (b)

[0055] b-1: N-ethanol-N-methyl dodecanamide

[0056] b-2: N-ethanol-N-methyl palm kernel oil fatty acid amide

[0057] Other Component

[0058] c-1: Coconut oil fatty acid diethanolamide

[0059] c-2: Coconut oil fatty acid monoethanolamide cl Formability

[0060] 30 mL of an aqueous solution of the surfactant composition wasprepared by diluting it in deionized water to 20-fold. The aqueoussolution was placed in a 300-mL mess cylinder having the inner diameterof 3 cm, equipped with a stop cock and shaken at 25° C. for 10 secondswith an amplitude having 10 cm 20 times. The volume (mL) of foam wasimmediately determined.

Storage Stability

[0061] The surfactant composition was allowed to stand at 0° C. for 1week and then the appearance was observed visually.

[0062] ◯: Uniformly clear with no change

[0063] Δ: Turbid

[0064]^(x): Separation, sedimentation or crystals' precipitation

Viscosity

[0065] The viscosity of the surfactant composition was measured at 25°C. with a standard B type viscometer. TABLE 1 Example Comparativeexample 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Composition of surface active agents(parts by weight) Component (a) a-1  18 20   a-2  20 20 a-3  16  20 a-4 13  16  20  16 a-5  14  14 20  15 Component (b) b-1  2  5  7  6 b-2  4 4  6 Other c-1  5 component c-2  4 Result of evaluation Bubble amount150 150 171 242 246 240 255 67.6 70 105 200 61 205 213 (mL) Storagestability ◯ ◯ ◯ ◯ ◯ ◯ ◯ Δ Δ Δ ◯ ◯ X X

[0066] TABLE 2 Example Comparative example 1 2 4 5 6 7 1 2 4 5 6 7Composition of surface active agents Component (a) a-1 18 20   a-2  2020   a-4  13  16  20  16 a-5  14  14 20    15 Component (b) b-1  2  5  7   6 b-2   4   6 Other c-1  5 component c-2   4 Viscosity (mPa · s)48 130 3400 3250 3870 2011 12.1 15.5 1023 14.8 5350 830

1. A surfactant composition comprising the following components (a) and(b): (a) at least one anionic surfactant selected from the groupconsisting of (1) to (3) defined below: (1) a sulfonate-type anionicsurfactant having an amide group or an ester group, (2) acarboxylate-type anionic surfactant, (3) a phosphate-type anionicsurfactant, (b) a compound prepresented by the formula (I):

where R¹CO— is a saturated or unsaturated acyl group having 6 to 24carbon atoms which may have hydroxy group, R² is an alkyl group having 1to 3 carbon atoms and R³ is a linear or branched chain alkylene grouphaving 1 to 6 carbon atoms or a linear or branched chain alkenylenegroup having 2 to 6 carbon atoms.
 2. The composition of claim 1, whereinthe ratio by weight of the component (a) to the component (b) is in arange of (a)/(b)=99/1 to 50/50.
 3. The composition of claim 1 or 2,wherein the component (a) is at least one selected from the groupconsisting of (2) the carboxylate-type anionic surfactant and (3) thephosphate-type anionic surfactant.
 4. The composition of claim 1,wherein the carboxylate-type anionic surfactant is at least one selectedfrom the group consisting of soap, an alkylethoxy carbonate and anacylated aminoacid salt.
 5. The composition of claim 1, wherein thephosphate-type anionic surfactant is a compound represented by theformula (V) or (VI):

where R⁹, R¹⁰, and R¹¹ are an alkyl or alkenyl group of 8 to 18 carbonatoms, M is hydrogen atom, an alkali metal, an alkaline earth metal,ammonium or an alkanol amine, plural M's being optionally either thesame as or different from one another, and x, y, and z are a numberranging from 0 to
 10. 6. The composition of claim 1, wherein thesulfonate-type anionic surfactant (1) is at least one selected from thegroup consisting of: an acylated amino sulfonic acid and a salt thereof,represented in the formula (II):

where R⁴CO— is a saturated or unsaturated acyl group having 6 to 24carbon atoms, R⁵ is a hydrogen atom or a linear or branched chain alkylgroup having 1 to 3 carbon atoms which may possess —OH, —CN or —COOH asa substituent, preferably hydrogen atom or methyl group, R⁶ is a linearor branched chain alkylene group having 1 to 4 carbon atoms or a linearor branched chain alkenylene group having 2 to 4 carbon atoms and M ishydrogen atom, an alkali metal, an alkaline earth metal, ammonium or analkanol amine; an acylated hydroxyl sulfonic acid and a salt thereof,represented by the formula (III): S0₃M (III) where R⁴CO— and M are thesame as defined above and R⁷ is a linear or branched chain alkylenegroup having 1 to 4 carbon atoms or a linear or branched chainalkenylene group of 2 to 4 carbon atoms; a sulfonated compound of alower alkyl ester of a fatty acid having 6 to 24 carbon atoms and a saltthereof and a sulfonated compound of a mono- or di-alkyl ester of adicarboxylic acid having 3 to 9 carbon atoms and a salt thereof. 7.Thecomposition of claim 5,wherein M is alkali metal.